They develop a safe and “promising” universal flu vaccine prototype

2023-04-21 02:42:04

The strains of the flu virus change every year and this makes it necessary to formulate new vaccines each season. The virus continues to cause thousands of deaths each year, and scientists must design new vaccines each year to cope with its rapid evolution. For this reason, for decades, efforts have been made to develop a “universal vaccine” that could protect against many different strains for longer periods of time, something that would be of great help for public health policies.

Now, a team of US scientists from the National Institute of Allergy and Infectious Diseases is publishing data from the first phase of a clinical trial of a new universal prototype that has been shown to be safe and “promising” in humans, reports EFE. The results of the study, carried out with 52 volunteers, are published in the journal Science Translational Medicine in an article in which its authors note that the vaccine candidate can generate immune responses that could protect against multiple strains of the flu virus.

Although more testing is needed in larger trials (Phase II, III, and IV), the new vaccine raised promising antibody and B cell responses. This indicates that “it could be an important step towards the long-awaited universal vaccine against influenza”, the authors summarize.

The H1ssF vaccine it is based on nanoparticles that contain the stem of the haemagglutinin H1 protein, a region that is usually conserved in different subtypes of the virus. The researchers administered one or two doses of the vaccine to 52 healthy adults between the ages of 18 and 70; 35 received a secondary boost after 16 weeks.

In general, the volunteers tolerated the vaccine well, showing only mild side effects, such as tenderness and headaches. The vaccine elicited a strong and long-lasting neutralizing antibody response that lasted for more than a year after vaccination.

The experimental vaccine provoked a rapid response of memory B lymphocytes and was able to induce the production of antibodies against different hemagglutinins of group 1 of the type A influenza virus.

For Inmaculada Casas, director of the respiratory virus and flu research group at the Carlos III Health Institute, who does not participate in the research, it is a very complete and high-quality work. “This study shows the results of a first phase 1 clinical trial in humans that has shown that in healthy adults the new H1ssF vaccine is safe, well tolerated, and immunogenic even without using adjuvant,” she summarizes to Science Media Center Spain.

The study authors speculate that the addition of adjuvants to the H1ssF vaccine could further enhance these immune responses, potentially providing greater protection to high-risk vaccine recipients during influenza epidemics or pandemics.